Causes
PID is caused by a bacterial infection in parts of the upper reproductive tract. The most commonly affected organs include the fallopian tubes, ovaries, and uterus. The bacteria most commonly associated with PID are Neisseria gonorrheae and Chlamydia trachomatis, but bacteria normally present in the vagina and cervix may also be involved. The cervix produces mucus that normally prevents bacteria from spreading to the upper reproductive tract. Researchers believe that the bacteria migrate upwards when this normal body defense is not working at its strongest (i.e., during ovulation and menses).
Risk factors for PID include:
- being sexually active
- being under age 25
- number of sexual partners (the more partners, the greater the risk)
- current or past STIs
- douching
- use of an intrauterine device (IUD) for birth control - it may slightly increase the risk of PID only if infected within the first 20 days of getting it placed (this risk is lowered when women are tested and treated for infections before getting an IUD)